Method for forming expansible bands for wrist watches and the like



June 2, 1964 A. SZEGLIN 3,135,085 METHOD FOR FORMING EXPANSIBLE BANDS FOR WRIST WATCHES AND THE LIKE 3 Sheets-Sheet 1 Filed Jan. 26, 1961 INVENTOR- flnopav ZEG E L L LI o \Pu 1M.

June 2, 1964 A. SZEGLIN 3,135,085

METHOD FOR FORMING EXPANSIBLE BANDS FOR WRIST WATCHES AND THE LIKE 5 Sheets-Sheet 2 Filed Jan. 26. 1961 INVENTOR- A Yapsv SZEG I'Y Arrom'ys A. SZEGLIN METHOD FOR F0 June 2, 1964 3,135,085

RMING EXPANSIBLE BANDS FOR WRIST WATCHES AND THE LIKE 3 Sheets-Sheet 3 Filed Jan. 26, 1961 INVENTOR. 14110 5.. 52664 BY 64 mm" AfTOQl/EXS United States Patent r 3,135,085 METHOD FOR FORMING EXPANSIBLE BANDS FOR WRIST WATCHES AND THE LIKE Andrew Szeglin, Hempstead, N.Y., assignor to Duchess Jewelry Mfg. Corporation, Hoboken, N.J., a corporation of New York Filed Jan. 26, 1961, Ser. No. 85,089 4 Claims. (Cl. 59-35) This invention relates to a method and machine for forming expansible bands for wrist watches and the like. Bands of this nature primarily are used to hold a wrist watch in place; however, it is desired to point out that they sometimes are employed by themselves as ornaments, and sometimes to hold other items of jewelry, eg., identification bars, in place.

One band of the aforesaid type is a pantograph, that is to say, a lazy tong, which consists of a series of pairs of cross-links, the cross-links of each pair being pivotally interconnected at their centers and the cross-links of successive pairs being pivotally interconnected at their ends so that the series of pairs of such cross-links will contract and expand concurrently. Suitable biassing means, such for instance as torsion springs, are associated with the pairs of cross-links to urge the connected pairs of crosslinks to contracted position. The basic set of cross-links customarily is not visible in a finished expansible band, it being the practice to cover the same with ornamental shells which often include precious metal.

Another band of the aforesaid type consists of two alternating series of links pivotally connected end-to-end only and biassed to contracted position.

The basic set of links will hereinafter be referred to as a frame or as a skeleton expansible band, it being understood by these terms, that reference is made to an expansible band without the covering shells.

It has been the custom heretofore to make skeleton expansible bands with a group of dies and a series of operations involving plural presses or the like in which the individual links of the skeleton band were separately formed (one type of link to a press) and thereafter transferred en masse to an assembly press. It has been proposed to expedite manufacture of such bands by a semiautomatic operation in which plural links were formed in separate presses and enough of the elements of each kind to make up one expansible band were jigged as they were made and were then transferred in groups, and in this manner simultaneously presented to an assembly press. However, all these previous methods and the machines on which they were practiced were essentially slow, bulky, expensive and clumsy, and needed consid- 3,135,085 Patented June 2, 1964 It is another object of the present inventionto provide a method of the character described which are fully automatic in operation and do not require any manual assistance in manufacture, transferral or placement of the parts of the band, manual aid being limited to maintenance of the machine, supplying rolls of strips and taking away erable skill and labor for proper performance, this being reflected in the comparatively high factory cost of expansible bracelets.

It is an object of the present invention to provide a method which avoid the foregoing drawbacks, that is to say which enable skeleton expansible bracelets to be made speedily in a small space, at a low cost and with a minimum of skilled help. i

It is another object of the present invention to provide a method of the character described which are continuous in operation, that is to say which make and assemble finished bands.

It is another object of the present invention to provide a machine of the character described which constitutes a comparatively simple die set that can be inserted in a conventional production machine including a reciprocable ram and an anvil so that it is adapted to be used in any power press.

It is another object of the present invention to provide a method of the character described which are precise and accurate in their operations and will produce expansible bands of good quality and durability.

It is another object of the present invention to provide a method of the character described for producing expansible band skeletons which are essentially conventional in construction so that they can be covered with standard ornamental shells by ordinary methods and machines and do not require special equipment for such purpose.

Other objects of this invention in part will be obvious and in part will be pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, arrangements of parts and series of steps which will be exemplified in the construction and process hereinafter described, and of which the scope of application will be indicated in the appended claims.

In the accompanying drawings, in which are shown various possible embodiments of this invention,

FIG. 1 is a top plan view of the principal operating elements of a machine constructed in accordance with the present invention;

FIG. 2 is a perspective view of a carrier block and its conveyor which enable the several operations of the machine to be carried out successively and continuously by transfer of the band parts from station to station;

' FIG. 3 is a perspective view of the first station, this being the one at which end rivets are placed on the carrier blocks;

FIG. 4 is a perspective view of the second station, this being the one at which center rivets are placed on the carrier blocks;

FIG. 5 is a perspective view of the third station, this being the one at which zig-zag cross-links are placed on the carrier blocks;

FIG. 6 is a perspective view of the fourth station, this being the one at which straight cross-links are placed on the carrier blocks; and

FIG. 7 is a perspective view of the fifth station, this being the one at which the rivets are headed.

Referring now in detail to the drawings, the reference numeral 19 denotes a machine constructed in accordance with the present invention, the same being so constructed as to progressively and continually manufacture a pantograph skeleton expansible band.

As noted hereinbefore, a typical pantograph skeleton includes a pair of cross-links. conventionally these are substantially flat strips, one of which is straight and the other of which is of zig-zag configuration, it being understood that the particular shape and configuration of the two cross-links is not a feature of the instant invention and that the cross-links only have been shown as straight and zigzag because these are one kind of customary shape. Hence, it specifically is to be understood that where said cross-links are described herein as straight and zig-zag this description is not limitative. In a typical pantograph skeleton frame two cross-links are pivotally interconnected at their centers, as by a rivet, to form a pair of cross-links, and pairs of cross-links are arranged in succession with suitable means, such for instance as rivets, pivotally interconnecting their ends whereby to form the pantograph, i.e. lazy tongs, construction. The cross-links further include protuberances for engagement with torsion springs which are mounted on the expansible band after the cross-links have been joined to one another in pairs and after the pairs have been interconnected to constitute skeleton frames.

' In general the present invention is carried out by providing a die set which is adapted tobe mounted in a standard power press or the like production machine and which die set includes means for feeding a plurality of flat metal strips to an assembly zone at which previously partially formed crosslinks (embryos) are successively (one after the other) severed from the strips and successively pivotally interconnected to one another so that the skeleton band is progressively formed at and fed away from the assembly zone.

In the specific form of the invention herein described four metal strips are fed to the assembly zone. One strip has the end rivets successively severed therefrom, the second strip has the central rivets successively severed therefrom, the third strip has the zig-zag cross-links successively severed therefrom, and the fourth strip has the straight links successively severed therefrom. Moreover'in this specific form of the invention the assembly zone is subdivided into four stations and the die set includes a moving carrier that progresses from station to station so that at the first station one set of rivets is severed from one strip and deposited on the carrier, at the second station another set of rivets is severed from pending ears 24 which are pierced to receive the pins 26 that pivotally join the links of the conveyer chain. The conveyer chain is so constructed and arranged that when a reach of the chain is straight, e.g. the horizontal upper reach, and when the upper surfaces 14 of the carrier blocks are horizontal and the side faces 38 of the blocks are vertical, the blocks will be juxtaposed and in contact, so that a series of the blocks presents a functionally unitary stationary carrier, the term stationary in this sense being used to indicate that the blocks are held against vertical and lateral movement although they are permitted translatory advancing movement from station to station in a horizontal plane.

The conveyor is advanced step-by-step for a distance which will soon be apparent; that is to say, the conveyer chain, and, therefore, the carrier blocks, are moved intermittently. The distance moved each step is equal to the width of a carrier block in the direction of movement of another strip and is deposited on the carrier, at the third 1 station one of the cross-links is severed from a third strip and is deposited on the carrier, and at the fourth station the second cross-link is severed from a fourth strip and is deposited on the carrier. A fifth station further is provided at which the rivets are headed to complete the assembly. However, it should be understood that this invention is not to be limited to the specific use of five stations or steps inasmuch as more or less stations and steps can be employed. Thus, since the basic skeleton pantographic expansible band constitutes five parts, to wit, two end rivets, one center rivet and two links, five strips can be fed to the assembly zone. Alternatively some of the parts can be combined, e.g. one, or more of the rivets can be formed integrally with one or both of the cross-links so that the invention can be practiced with a lesser number of stations and steps, for example, as few as three stations and steps. It, therefore, will be appreciated that the method and machine now to be described in detail are exemplificative rather than limitative.

The moving carrier of the present invention constitutes a large number of individual jointly operating carrier blocks 12 which, as shown in FIG. 1, are located in sideby-side abutment at the assembly zone, being suitably mounted: and actuated so as to progressively move through said zone and while in said zone to act as an integral unit. In particular, each carrier block (see FIG. 2) is made of a hardened piece of tool steel that has a generally plane upper surface 14 which is provided with positioning pins and reliefs for facilitating manufacture of the e'xpansible hand.

All of the carrier blocks are formed on their under surface with suitable means for securement to a transport means such, for instance, as an endless conveyor chain 16. Said conveyor chain is trained about a pair of sprockets (not shown) journalled to turn about horizontal axes at the entrance and delivery ends 18, 2% of the machine 10. The upper horizontal reach 22 of the chain passes through the assembly zone shown in FIG. 1. To secure the carrier blocks to the conveyer chain, each of said blocks is provided with two spaced downwardly dethe conveyor, so that each time the conveyor moves to advance the carrier blocks one step, each carrier block in the horizontal reach will take on the position formerly occupied by the preceding block. Thus individual carrier blocks will advance step-by-step through the assembly zone shown in FIG. 1.

To insure accurate positioning of the carrier blocks at each of the five individual stations, each said carrier block is formed with a V-shaped vertical gib 28 at each end thereof.

In order to firmly support the carrier blocks with their upper faces in a common horizontal plane as they pass through the assembly zone so that said blocks can function as anvil elements as well as carriers, each carrier block is formed on each end face with a rectangular horizontal slot 30. At the front and back of the die set 19 rigid stationary bars. 32 of rectangular cross-section are provided, said bars snugly and slidably fitting into the slots 30 of all the carrier blocks at the various assembly stations.

The upper plane surfaces 14 of the carrier blocks are narrow and elongated end-to-end, that is to say, transversely of the direction of movement A of the carrier blocks and conveyor chain through the assembly zone.

More particularly, the longitudinal axes of the carrier blocks are at an angle of about 65 to said direction of movement A. This particular angle is not a criterion of the invention but is the angle at which the particular pantograph expansible band herein shown has its straight cross-links disposed with respect to the longitudinal axis of the band when the band is almost fully contracted.

For the purpose of clearing certain auxiliary mechanisms, the upper surface of each carrier block is relieved at various portions as by the provision of slots 33, 34 which are parallel to direction of movement A, and of notches 36 in the broad side faces 38 of the blocks.

Moreover the upper plane surfaces of every carrier block includes upwardly extending erect stub positioning pins 40, 42, 44. The pins 40, 42 are outermost and the pin 44 is located midway between them. All three pins lie on the longitudinal central axis of the top face of the carrier block. The locations of these pins and the spacing between them is such that they are at the three axeshf rotation of the pivotal means which connect the centers and ends of the pantograph links when the latter are almost fully contracted. In particular, the three pins on each carrier block are vlocated in the aforesaid pivotal positions with respect to the straight cross-link of a pantograph skeleton band. The outer pins 40, 42 are more slender than the central pin 44 because in the expansion band made by the machine 10 the hollow rivets at the ends of the cross-links are smaller than the hollow rivets at the centers of the cross-links.

Referring to FIGS. 1 and 3, at the first station a long thin strip 46 is fed lengthwise to the machine 10 in the direction indicated by the arrow B. Said strip is formed from the metal of which it is desired to fabricate the end (outer) rivets 48, i.e. the rivets which ultimately will pivotally interconnect the ends of adjacent pairs of cross-links. The strip 46 is fed intermittently into the machine 10. Before the forward end of the strip reaches the working portion of the first station it has had formed therein, in any suitable fashion, e.g. by progressive steps of deep drawing, hollow rivet shanks 50. These shanks are so positioned in the strip 46 that when said strip is stationary above the two carrier blocks at the first station one shank will be directly above and centered with respect to an outer pin 40 on one of the carrier blocks and another shank will be directly above and centered with respect to the outer pin 42 on the other and adjacent carrier block then at the first station.

It may be mentioned that the shanks 50 can be formed as a part of the operation of the machine that is to say the machine 10 may include progressive type drawing dies which form the shanks 50 to the desired shapes and dimensions and in the proper positions as the strip 46 is fed toward the line of carrier blocks at the first station. Alternately, the strip 46 may have the shanks 50 formed therein in a separate operation in another machine where it may be accomplished in a press or with rolling dies. In either event, the forward end of the strip 46 as it approaches the line of carrier blocks has had preformed in it in the proper positions to be placed on the outer pins 40, 42, embryo rivets, i.e., hollow shanks 50 which are fully preformed and heads 52 which still are part of, i.e., integral and in one piece with, the general plane of the strip 46. Said heads may be partially formed, as indicated, into their ultimate shape which may be of an arcurate toroidal configuration, or simply may be flat, depending upon the type of rivet head it is desired ultimately to provide in the finished skeleton band.

At the first station, in each cycle of operations of the machine 10 two outer rivets 48 headed at their lower ends only are cut away from the strip 46 and deposited on the positioning pins 40, 42 of the two adjacent carrier blocks at said station. That is to say, one rivet is deposited on a positioning pin 40 of one block and the second rivet is deposited on the pin 42 of the adjacent block. Suitable means is included for the foregoing purpose. Such means comprises a pair of hollow blanking punches 54, 56. One punch 54 is vertically aligned with a positioning pin 40 of one carrier block at the first station and the other punch 56 is vertically aligned with the pin 42 of the other adjacent block at the first station.

The punches 54, 56 are functionally integralwith opposed pilot teeth 58 that engage the gibs 28 of the two carrier blocks 26 at the first station during the blanking operation, i.e., the pilot teeth vertically reciprocate with and slightly operationally lead the blanking punches 54, 56. Said two blanking punches 54, 56 and the pilot teeth 58 are mounted upon the upper part of the die set which constitutes the machine 10, said upper part being secured, for example, to the ram of a conventional power press.

It will be appreciated that the punches 54, 56 cannot, per se, cut out the heads of the rivets 48. It also is necessary to provide a fixed blanking anvil 60 above the moving carrier. This fixed anvil is located at the first station beneath the strip 46 and is formed with a pair of blanking openings registered with the punches 54, 56 and with the pins 40, 42 of the two carrier blocks at the first station beneath these punches. In the actual construction of the machine the first station fixed anvil 60 has its top surface immediately below the undersurface of the strip 46 and its undersurface just barely clears the tips of the positioning pins 40, 42, 44 so that the openings in said anvil 60 have their lower terminals at a level just above the tips of the pins 40, 42. Such arrangement enables the rivets sheared from the strip 46 to be deposited on the positioning pins 40, 42 without loss of control, since when the rivets are separated from the strip they are maintained in position on the blanking punches 54, 56 by the side walls of the openings in the blanking anvil 60 and thereafter as soon as they emerge from the openings in the blanking anvil the hollow shanks of the rivets are received on the positioning pins. Moreover, each of the blanking punches 54, 56 is hollow, thus enabling the shanks of the rivets to be received therein during the blanking operation.

The provision of an axial bore in each blanking punch facilitates the inclusion of strippers. These latter take on the form of plungers 62, one for each of the punches 54, 56. The plungers are snugly slidable within the lanking punches. Said plungers are actuated in part with and in part independently of, the blanking punches. When the blanking punches are in their uppermost position the lower tips of the plungers are retracted, i.e. spaced upwardly from the lower tips of the punches, thereby to leave a clear space in each punch for admission of the shank 50 of the embryo rivet that is to be cut out. When the punches 54, 56 descend the plungers 62 may be moved downwardly therewith and at the same rate. This movement continues until the punches have deposited the blanked out rivets 48 on the positioning pins 40, 42. Thereafter at the blanking punches 54, 56 are retracted, i.e. retrogradely moved upwardly, the plungers are permitted to dwell with their lower ends resting on the unheaded tops of the shanks of the rivets that have been deposited on the positioning pins 40, 42. This action strips the blanking punches from the hollow rivets and allows these two rivets to remain on the carrier blocks 12 at the first station. Subsequently as the punches 54, 56 continue their upward travel the plungers 62 move upwardly with the blanking punches and thereafter the strip 46 is disengaged. Next the pilot teeth 58 are disengaged from two individual carrier blocks at the first station. Now said two carrier blocks are free to be fed forward one step and the strip 46 is free to be fed forward one step in order to enable a fresh pair of rivets 48 to be cut from the strip and deposited on the next pair of carrier blocks than at the first station. Thus it will be apparent that as the moving carrier leaves the first station there will have been provided on each individual carrier block a pair of head down outer rivets 48 which are in position for the further operations now to be described.

In order to prevent accumulation of long lengths of waste .stock from the strip 46 once the rivets 48 have been cut therefrom, a shearing blade 64 is mounted to reciprocate with the blanking punches 54, 56. Said blade cooperates with a shearing anvil 66 located in the path of travel of the strip 46 after it has left the first station. Accordingly, each time that the punches 54, 56 descend, an end portion of the Waste strip is chopped away as scrap.

The second station of the assembly zone is shown in FIGS. 1 and 4. This second station is very much like the firststation and differs therefrom only in that there is formed and deposited thereat on the central positioning pin 44 of successive carrier blocks central rivets 68 with one end only thereof head end down. More particularly, at the second station a long thin strip 70 isfed lengthwise to the machine 10 in the direction indicated by the arrow C. Said strip is formed from the metal of which it is desired to fabricate the center rivets 68, i.e. the rivets which ultimately will pivotally interconnect the centers of the two cross-links of any given pair of such links. The strip 70 is fed intermittently into the machine 10 at the second station. Before the forward end of the strip 74) reaches the working portion of the second station it has had formed therein, in any suitable fashion, e.g. by progressive steps of deep drawing, hollow rivet shanks 72. These shanks are so positioned in the strip 70 that when the strip is stationary above the carrier block 12 at the second station one shank will be directly above and centered with respect to the center positioning pin 44 on the carrier biock then at the second station.

As in the case of the rivets 48,'the shanks 72 can be formed as part of the operation of the machine that is to say, the machine 10 may include progressive type drawing dies which form the shanks 72 to the desired shape and dimensions and in the proper positions as the strip 70 is fed toward the moving carrier. Alternatively, the strip 70 may have the shanks 72 formed therein in a separate operation in another machine where it may be accomplished in a press or with rolling dies. In either event, the forward end of the strip 70 as it approaches the moving carrier has had preformed in it in the proper positions to be placed on the center pins 44 of successive carrier blocks, embryo rivets, i.e. shanks 72 which are fully preformed and heads 74 which still are part of, i.e. integral and in one piece with, the general plane of the strip 70. Said heads may be partially formed, as indicated, into their ultimate shape which may be of an arcuate toroidal configuration, or simply may be flat, depending upon the type of rivet head it is desired ultimately to provide in the finished skeleton band.

At the second station, each cycle of operations of the machine 10, one central rivet 68 is cut away from the strip 70 and deposited on the center positioning pin 44 of the carrier block at the second station with its headed end lowermost. This is accomplished by means of a tubular blanking punch 76 and anvil 78 similar to the blanking punches 54, 56 and anvil 60 except of course for the size of the punch and of the anvil opening which are proper to sever a rivet 68 from the strip 70. A plunger 80 nested within the punch 76 strips the rivets 68 from said punch in a manner which has already been described with respect to the rivets 48. The second station also is provided with pilot teeth 82 that cooperate with the gibs 28 on the carrier block at said station to hold it exactly in place during the punching and depositing of the central rivet 68. Furthermore, at the second station there is provided a shearing blade 84 and cooperating anvil 86 which cut off scrap 88 from the end of the waste portion of the strip 70 each time that a rivet 68 is blanked therefrom and is placed on the moving carrier.

As the carrier blocks leave the second station each block will have mounted thereon, as is quite clear in FIG. 3, two end rivets 48 and a central rivet 68 each with one head only and that head lowermost.

The third station is shown in FIGS. 1 and 5. At this station a long thin strip 90 is fed lengthwise to the machine 10 in the direction indicated by the arrow D. Said strip is formed from the metal of which it is desired to fabricate the zigzag cross-links, there being one such cross-link in each pair of cross-links forming the pantographs skeleton frame shown in the accompanying draw ings. The strip 90 is fed intermittently into the machine 10 at the third station. Before the forward end of the strip 90 reaches the working portion of the third station it has had formed therein, in any suitable fashion, the configuration (with the exception of peripheral contour) that is desired for the zig-zag link. This configuration characteristically includes three openings for the end and central pivotal connections and protuberant edge tangs one of which ultimately serves as an anchor for an end of a biassing spring. Said configuration can be imparted in any suitable fashion, e.g. by progressive steps. As shown, the strip 90 is provided, as by perforating in a preforming operation, successive groups of three aligned openings 92, 94 and 96, the openings 92, 94 being for reception of the shanks of the end pivotal rivets 48 and the opening 96 being for reception of the shank of the central pivotal rivet 68. The erect anchoring edge tangs 98 are provided by means of a suitable forming die. The three openings 92, 94, 96 in each group of openings are properly spaced apart to receive the end and central pivotal connections.

The openings 92, 94 and 96 and tangs 98 can be formed as part of the operation of the machine 10, or they may be formed in a separate machine. In either event, the forward end of the strip as it approaches the moving carrier has had preformed in it in the proper positions to be placed on the rivets 48, 68, embryo zig-zag cross-links which are fully preformed (except for their peripheral contour and separation from the strip and except for the erection of the tangs 98) and are still part of, i.e. integral and in one piece with, the general plane of said strip.

At the third station, in each cycle of operations of the machine 10, a zig-zag cross-link is cut away from the strip 90 and deposited on and across three adjacent carrier blocks 12 with an end opening 92 received on the shank of an end rivet 48 on an endmost carrier block at the [third station, with the central opening 96 received on the shank of the central rivet 68 on the center carrier block at the third station and with the other end opening 94 received on the shank of a rivet 48 on the other endmost carrier block. The two said end rivets are at oppo site ends of their respective blocks. In other words the zig-zag cross-link 100 bridge three carrier blocks diagonally and engages one previously deposited rivet on each of these three blocks.

To cut away zig-zag cross-links from the strip 90 at the third station a blanking punch 102 is provided the transverse cross-section of which corresponds to the desired peripheral shape of the zig-zag link to be blanked out. The punch 102 is properly located with respect to the previously formed openings 92, 94, 96 to correctly orient these openings in the blanked out link 100 and, of course, is similarly correctly located with respect to the positioning pins 40, 42, 44 of the three carrier blocks then at the third station.

Reciprocable with the punch 102 are a pair of pilot teeth 104, 105 that engage the gibs 28 of the two endmost carrier blocks 12 on oposite ends thereof at the third station prior to and during the operation of blanking out the zigzag cross-links 100. Cooperating with the punch 102 is a blanking anvil 106 which is directly beneath the strip 90 and has formed therein a blanking opening 108 that matches the contour of the punch 102. The undersurface of the blanking anvil 106 barely clears the previously deposited rivets 48, 68 so that as a zig-zag link 100 is released from the control of the blanking anvil it will, before it has had an opportunity to fly free, be mounted on the shanks of the end and central rivets 48, 68 of the three carrier blocks then at the third station.

It may be mentioned that the undersurface of the punch 102 is relieved to clear the upstanding shanks of the rivets 48, 68.

Stripping plungers 110 are reciprocable in bores in the punch 102 to hold a freshly placed zig-zag link 100 on the carrier blocks at the third station when the punch 102 first starts its retrograde motion.

As the carrier blocks leaves the third station they will have seated thereon the endmost rivets and central rivets on the positioning pins 40, 42, 44 and there will be threaded over the shanks of these rivets a series of parallel spaced zig-zag links 100 (see FIG. 1).

All the rivet and link strips 46, 70, 90, and one more strip still to be described, and the carrier blocks 12 are stationary while the sundry blanking punches and strippers are in contact with the strips and the blanking punches and strippers are clear of the strips when the strips and carrier blocks are advancing, suitable timing arrangements (not shown) being provided to synchronize the feeds of the strips and the carrier blocks with the punches and strippers.

The third station also has associated with it a shearing blade 112 and a shearing anvil 114 to chop scrap from the waste end of the strip 90.

The fourth station is shown in FIGS. 1 and 6. Since the mechanisms atthis station are essentially similar to the mechanisms at the third station, the fourth station will not be described in detail. At the fourth station a long thin strip 116 is fed lengthwise to the machine 10 in the direction indicated by the arrow E. Said strip is formed from the metal of which it is desired to fabricate the straight links 118; these being the second series of crosslinks (the zig-zag links are the first series). The strip 116 is fed into the machine while the intermittently movable carrier is stationary.

Before the forward end of the strip 116 reaches the working portion of the fourth station, it has had previously formed therein groups of three openings 120, 122, 124, the openings 120, 122 being properly sized and located to correspond to the openings for the end pivotal connections of a straight cross-link 118 and the openings 124 being suitably sized and located to correspond to the pivotal central connection of a straight cross-link. The strip also is provided with openings 126 partially covered by angled ears 127 such as are conventionally found in a straight link for anchoring ends of biasing means. The groups of openings 120, 122, 124 are so positioned in the strip 116 that when said strip, is stationary above the carrier block at the fourth station the openings 120, 122 will be directly above the end positioning pins 40, 42 of said block and the opening 124 Will be directly above the central positioning pin 44 of said block.

This strip 116 can be formed in the machine 10 or independently thereof and, in either event, as it approaches the working position of the fourth station it has had preformed therein in proper position to be placed on the shanks of the rivets 48, 68 of the carrier block at that station embryo straight links 118 which at the time still are part of, i.e. integral with, the general plane of the strip 116.

At the fourth station a punch 128 and anvil 130 are formed to a shape such that each time the punch 128 descends it will freshly cut from the strip 116 with the aid of the anvil 130 a cross-link 118 which thereupon is forced through the opening in the anvil 130 to be deposited on the shanks of the rivets of the carrier block at that station and angularly crossing three zig-zag crosslinks 100, previously successively mounted on the pins of said carrier block at the third station.

Stripping plungers 131 disengage the freshly deposited straight cross-links from the plunger at the fourth station. To hold the carrier block stationary during the blanking of a straight cross-link the punch 128 is provided with pilot teeth 132, 134 that engage the gibs 28 of the carrier block at said station. The undersurface of the punch 128 is recessed to prevent interference with the shanks of the previously deposited rivets 48, 68 the upper ends of which as they leave the fourth station project through the zig-zag and straight cross-links.

As the carrier blocks leave the fourth station they have mounted thereon an almost complete pantograph expansible skeleton frame; that is to say, all the elements of said frame now will be in proper relative position on the carrier blocks, these constituting the end and center rivets and the successive pairs of cross-links. However, the upper ends of the rivets are not yet headed and until they are the skeleton frame is unfinished.

At the fifth station (see FIGS. 1 and 7) the protruding upper ends of the rivets 48, 68 are headed. To this end said fifth station includes three heading punches 134, 136, 138 respectively aligned with the endmost and center rivets on a carrier block 12 then at said fifth station. The heading punches are individually conventional, which is to say they are provided, for example with reduced diameter annularly filleted spreading tips 140. The centers of the tips are hollow to permit them to clear the positioning pins 413, 42, 44. Each time said three heading punches descend they will head the upper ends of all three rivets on the carrier block then at the fifth station, said block being held in fixed position by pilot teeth 142 that engage the gibs 28 of the carrier block then at said station and reciprocate with said heading punches.

All the pilot teeth, as is customary, slightly lead their associated punches, that is to say, they engage thegibs 28 before the punches near the carrier blocks.

In accordance with an ancillaryfeature of the invention means is included at the fifth station to intermittently render the heading means ineffective, such action having the effect of separating the pivotally interconnected crosslinks into discrete groups each of which is a dilferent skeleton frame. For example, if a given skeleton frame is to include a certain number of pairs of cross-links, after this number of pairs of cross-links have ad their centers and end rivets headed, the operation of the fifth station is momentarily suspended, e.g. for two cycles of operations. Thereby the pivotal means (rivets) for two pairs of cross-links are rendered ineffective so that two successive groups of cross-links can be separated from one another after they leave the machine 10.

It may be mentioned that an equivalent effect can be secured by temporarily suspending effective operation of any one of the other stations; but thevsuspension of operations at such other stations cannot be accomplished as easily and simply as it can be accomplished at the fifth station while no strip feeding means is present;

In order to enable the fifth station to halt its effective operation, the three heading punches 134, 136, 138 are mounted on a common horizontal plate 144 from the upper surface of which a vertical shaft 146 fixedly ex tends. Said shaft is rotatably received in a vertically reciprocating carrier 148. The shaft 146 is displaced from the three heading punches 134, 136, 138. Suitable means such as an electro-magnet (not shown) is provided to oscillate the common plate 144 about the axis of the shaft 146 as indicated by the arrow F.

In the position of the plate 144 shown in FIG. 7 the heading punches are registered with the rivets 48, 68 on the carrier block then at the fifth station; however if the plate 144 is swung through a predetermined arc in the direction of the arrow F, the three heading punches will, when the carrier 148 descends, pass by, i.e. clear, all parts of the cross-links and rivets on the carrier blocks so that no heading operation will be performed.

The plate 144 is oscillated as aforesaid under the control of a link 15% by theelectro-magnet which in turn is intermittently energized by a counter that counts the number of times that the heading punches descend while in operative position and then, after the predetermined number of heading operations have been performed, energizes the electro-magnet so as to oscillate the plate 144 to render the heading punches ineffective for two cycles of operation. Thereupon the electro-magnet is deenergized to swing the plate back to its operative position and the heading operations are automatically resumed.

The cross-links leaving the fifth station are now, as will be apparent, completely assembled and operatively integrated in separate groups of the desired number of pairs.

Thereafter the carrier blocks reach the sprockets at the far end of the assembly zone and turn around to the lower horizontal reach (not shown) thereby dofiing the assembled cross-links by gravity with the assistance, if desired, of an air blast.

It thus will be seen that there is provided a device which achieves the several objects of this invention, and which is well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment above set forth it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described the invention, there is claimed as new and desired to be secured by Letters Patent:

1. A method for progressively forming expansible bands including two series of different kinds of links arranged at angles to one another and pivotally interconnected at their ends, said method comprising progressively moving a carrier from station 'to station through an assembly Zone, supplying long strips to at least three different stations, at one station successively cutting from one strip and depositing interconnecting pivotal means on the carrier, at a subsequent station successively cutting from another strip one after another of a series of first links and depositing saidfirst links on said carrier in interengagement with said previously deposited pivotal means and with said first links spaced from one another, at a further subsequent station successively cutting from a further strip one after another of a series of second links and depositing said second links on said carrier with the ends of each second link overlying opposite ends of and spanning the space between a different pair of previously deposited first links and with said ends and in interengagement with said pivotal interconnecting means, and finally at a station subsequent to the cutting and depositing stations successively heading the pivotal interconnecting means on the carrier whereby to progressively form on the carrier an expansible band in said assembly station.

2. A method for progressively forming expansible bands including two series of difierent kinds of links arranged at angles to one another and pivotally interconnected at their ends, said method comprising progressively moving a carrier from station to station through an assembly Zone, supplying long strips to at least three different stations, at one station successively cutting from one strip and depositing interconnecting pivotal means on the carrier, at a subsequent station successively cut ting from another strip one after another of a series of first links and depositing said first links on said carrier in interengagement with said previously deposited pivotal means, at a further subsequent station cutting from a further strip one after another of a series of second the ends of each second link overlying opposite ends of and spanning the space between a different pair of previously deposited first links and with said ends in interengagement with said pivotal interconnecting means, at a station subsequent to the cutting and depositing stations successively heading he pivotal interconnecting means on the carrier whereby to progressively form on the carrier an expansible band in said assembly station, and finally temporarily halting the heading operation after a predetermined number of heading operations so as to separate successive expansible bands.

3. A method for progressively forming expansible and spanning the space between a different pair of links of the first deposited series and with the pivotal interconnecting means interengaging the ends of the links of the two series, and at a station subsequent to the depositing stations successively heading the pivotal interconnecting means on the carrier whereby to progressively form on the carrier an expansible band in said assembly Zone.

4. A method for progressively forming expansible bands including two series of different kinds of links arranged at angles to one another and pivotally interconnected at their ends, said method comprising progressively moving a carrier from station to station through an assembly Zone, supplying to a first station a long strip having embryo rivets integrally formed therein, successively cutting rivets from said first strip and depositing the rivets successively on the carrier, supplying to a subsequent station a second strip having embryo first links integrally formed therein, successively cutting first links from the second strip and successively depositing said ,first links on the previously deposited rivets, supplying '*to a further subsequent station a third strip having embryo second links integrally formed therein, successively cut- 1 ting second links from the third stripand progressively depositing said second links on the previously deposited g rivets with the ends of each second link overlying oplinks and depositing said second links on said carrier with posite ends of ,a different pair of previously deposited first links and with said ends engaging previously deposited rivets, and subsequent to the cutting and depositing operations successively heading the rivets on the 4() carrier whereby to progressively form on the carrier an expansible band in said assembly zone.

References Cited in the file of this patent UNITED STATES PATENTS Heftler May 19, 1942 2,829,488 Valli Apr. 8, 1958 2,961,752 Jorgensen et a1 Nov. 29, 1960 

1. A METHOD FOR PROGRESSIVELY FORMING EXPANSIBLE BANDS INCLUDING TWO SERIES OF DIFFERENT KINDS OF LINKS ARRANGED AT ANGLES TO ONE ANOTHER AND PIVOTALLY INTERCONNECTED AT THEIR ENDS, SAID METHOD COMPRISING PROGRESSIVELY MOVING A CARRIER FROM STATION TO STATION THROUGH AN ASSEMBLY ZONE, SUPPLYING LONG STRIPS TO AT LEAST THREE DIFFERENT STATIONS, AT ONE STATION SUCCESSIVELY CUTTING FROM ONE STRIP AND DEPOSITING INTERCONNECTING PIVOTAL MEANS ON THE CARRIER, AT A SUBSEQUENT STATION SUCCESSIVELY CUTTING FROM ANOTHER STRIP ONE AFTER ANOTHER OF A SERIES OF FIRST LINKS AND DEPOSITING SAID FIRST LINKS ON SAID CARRIER IN INTERENGAGEMENT WITH SAID PREVIOUSLY DEPOSITED PIVOTAL MEANS AND WITH SAID FIRST LINKS SPACED FROM ONE ANOTHER, AT A FURTHER SUBSEQUENT STATION SUCCESSIVELY CUTTING FROM A FURTHER STRIP ONE AFTER ANOTHER OF A SERIES OF SECOND LINKS AND DEPOSITING SAID SECOND LINKS ON SAID 